Thermometer



.. 0. .lDmZ. 9 DEI DnT' `Anrn. GMM .LON .LMU IR] HED. HF. ETH Cl Jan. 9, 1923.

Ihm/"muoia:

Patented dan. 9, i923.

NITE-:D STATES PATENT ofFrl'cE'.

, ERICH HILLIGARDT, OF FRIEDRICHSHAFN, GERMANY, ASSIGNOR T0 THE FIRMZ LUFTSCHIFFBAU VZIEIEEEIILIIN, GESELLSCHAFT MIT BESCHRANKTER HAFTUNG, OF

FRIEDRICHSHAFEN, GERMANY.

THERMOMETER.

l Application iled .Tune 28, 1920. Serial No. 392,428.

To all whom t may concern.'

Be it known that I, ERICH HILLIGARDT, a citizen of the German Einpire, residing at Friedrichshafen,- Germany, have invented certain new and useful Improvements in Thermometers, lof which the following is a specification. y

My invention refers to a thermometer adapted for use in aerial vehicles and allowing to ascertain easily and as exactlyas possible the temperature of the outer air from the ldrivers seat or from the observaout the accuracy of-its indications being impaired thereby. I effect this by enclosing the greater part at least of the thermometer within a casing connected at one end to' an air pipeadapted to be set in the'direction of travel, said casing being provided at its other end with outlet openings for the air passing along the thermometer. manner the thermometer may be arranged at a place affording protection against the wind and allowing it to be read off easily. The air led on to it by a ipe whose free end may assume the form of a nozzle.

This manner of measuring the temperature offers special advantages'. inasmuch as the iniuence of the sun rays is avoided.

' Artificial lighting can easily beprov-ided 'by means of a lamp disposed in close Aproximity to the scale if care is only taken to cause the air utilized for measuring purposes to carry off the heat directly generated by the lamp, the heat generated by radiation in lamps of the size employed in this case being practically nil.' Y

IA further `prefer Ysurrounding the thermomet'er by a complete'h'casing having its front part cut out in such a manner that on the thermometer being lodged therein, the frontal surface of the latter is applied to In thisV differing sizes I,A prefer inserting between it and the casing a slotted strip of felt or the like, such strip serving at the saine time as a protection against' air and light peering through fromA without. Y

In the drawings aiixed to this speciication and forming part thereof an instrument according to my invention is illustrated by way of example. In the drawings- Fig. l is a vertical longitudinal section.

Fig. 2 is a cross section n. the line 2 2 (Fig. 1`)

Referring to the drawings, A is the casing and B is a pipe removably connected thereto. C is a supporting spring fixed to the casing at a? and d is a spring fixed thereto at c2, said springs serving to press the thermometer E against a strip of felt F inserted between it and the slotted front wall of the casing. Anincandescent lamp Grv disposed in the rear wall of the casi is fed with current through a conductor The air enters into thev free end 1, bent in the direction of travel of the pipe B and flows through it and-through the casing A, leaving this latter through openings Z4 after having cooled the lamp. Another portion of the air escapes through the openings a5.

in the cover as; In order that the springs C D may not form a hindrance to the passage of the air slots, vc1 d1 are provided therein.

The pipe B is connected with the casing i I in 'such a manner as to be 'easily replace and swung around.

I claim: l. The combination with a and a protective casing surrounding the saine, of air admitting and discharging meansl on said casing adjacent the ends of the thermometer, spring acting supporting thermometer mea-ns on one of the wallsof the casing engageable with the thermometer, and resilient supporting means spaced from each other and opposite the spring acting means on the opposite wall of the casing.

2. The combination with a thermometer and a protective casing therefor, of air admitting and air discharging means on said casing adjacent the ends of the thermometer, spring acting apertured supporting means spaced from each other upon one wall of the .3. Thecombination With a thermometer" of a substantially, tubular frontally apen' tured enclosure ,for said thermometer,` aper-v tured spring acting supporting means upon said casing engageable near the -ends of the thermometer, additional resilient supporting means opposlte the,rstm'entioned sup- .porting'ineans connected to the easing and` engageable with the thermometer, air ad- `mitti-ng means on the casing near the thermometer bulb, and air outlets on said casing. 4; In a heat'measurlng device 1n 'combination, a thermometer, a casing partly`in engagement with said thermometer and.' partly spaced therefrom andgparallel there-- said casing.

to, and` adapted to expose the scale thereof,

an electric lamp, air outlets near said lamp,

and meansl connected withy said -casingfor conducting theouter air from the bottom end thereof past the thermometer bulb and 'along the thermometer tube, and supportthermometer mounted oning means for the '5.'In` an aircraft car in combination, a i

thermometer and a casing surrounding it, both beingarranged Within the said car, and a ipe connected With the bottom end of saidpcasingv and projecting through the jcal'. Wallinto the 4outer air,L the free `end of "said pipe being turned in the direction of travel. y In testimony whereof I aflix my-signature.

' y ER-10H HILLIGARDT. 

